Telegraph system



March 30, 1937. D. E. BRANSON Er AL 2,075,422

TELEGRAPH SYSTEM Filed April 4, 1955 StatiO-m f Two-wa Iii ne INVENTORS 2573mm nzzzmzmw BY ME? szel 0 ATTORNEY Patented Mar. 30, 1937 UNITED STATES PATENT OFFICE TELEGRAPH SYSTEM Application April 4, 1935, serial No. 14,114

Claims. This invention relates to telegraph systems and more particularly to improved repeater arrange-' ments utilized in such systems.

In the arrangements of this invention the tele- 5 graph repeater comprises a plurality of gas filled discharge tubes and circuit arrangements therefor whereby the usual magnetic relay arrangements may be eliminated. The arrangements or tures of theinvention will appear more fully from the detailed description thereofhereinafter given.

The invention may be more fully understood from the following description, together with the accompanying drawing, in Figures 1 and 2 of v. which are shown circuit diagrams illustrating a preferred embodiment of the invention and a modification thereof.

In Fig. 1 is shown' a telegraph system interconnecting the stations A and B. At station A is shown a receiving circuit L2. Connected in each side of the receiving circuit La are the gas filled discharge tubes RB and'RA. These gas filled discharge tubes would have a common plate circuit which would be completed through the primary winding of a transformer I, the sending key 8, and battery B3. In the portion of the plate circuit individual to tube RB there would be provided the sounder 6. Connected to the transformer I would be a sending circuit L1. This sending circuit would have included in each side thereof the gas filled discharge tubes SB and SA. The operation of the tubes SB and SA serves to apply marking or spacing signals to the sending circuit 1-1.. In the receiving circuit the tubes RB and RA respond, respectively, to marking or spacing signals transmitted over the receiving circuit L2. At the station B would be provided apparatus. identical to that at the station A.

Accordingly, at station B similar reference 'char- RB to be made'more positive through potentiometer Pi. This will cause the tube RB to 0p erate and become conductive, thus permitting a direct current to fiow over the following circuit from ground, battery B3, contacts of key 8, primary winding of transformer l, winding of sounder 6, resistance Ra, plate and filament tube RB to ground. This will operatethe sounder 6 at station A. when the tube RB becomes con-' ductive, the potential on the plate drops from the full battery potential of battery B: to the normal sustaining voltage needed to maintain the tube conductive. When this takes place, the plate of tube RA,,which tube was previously conductive, is made suihciently negative with respect to its cathode to cause the tube RA to be extinguished. This is due to the connection of the condenser Ci.

between the plates of the tubes RB and RA.

This condenser arrangement, whereby the operation of either of the tube RB or RA will cause the release of the other tube, is an arrangement well known in the art. The impedance of R3 and the winding of sounder 6 should be duplicated by the impedance of the winding 5 and the resistance R4. With these impedances equal there will be no potential generated in the secondary winding of transformer I from the primary winding thereof when signals are being received. Accordingly, the reception of signals will have no effect on the sending circuit L1 and the received signals will not be transmitted back over the line. When a spacing signal is received over the receiving circuit In the tube RA will operate and become conductive and by means of condenser '01 will cause the tube RB to be extinguished. This willreduce the current through the sounder 6 to zero and the sounder will be released. However, as has been pointed out, no change in current flow through the primary winding of transformer I will take place and thesignals will not be repeated back over the line. 1

v Signals may be transmitted from the station A to the station B when a marking signal is applied to the receiving circuit L2. As heretofore pointed out, a marking signal caused the operation of tube RB; The opening and closing of the key 8 will 4 now cause a variation in the current flow through the primary winding. of transformer I and will furthermore operate the sounder 6. When the key 8 is closed the 'current fiow through the transformer I will fiow through resistances R5 and Rs .in such a direction as to operate the tube SB.

The operation of the tube SB will cause a current to flow from battery B5 through resistance R9, and from the plate to the filament of tube SB to ground. This will transmit a marking impulse over the sending circuit L1. When the key 8 is opened the current flow through the transformer 1 will flow through resistances R5 and Rs in such a way as to operate the tube SA. The operation 5 of tube SA will cause a current to flow from battery 135 through resistance R7 and the plate and filament of tube SA to ground and this will apply a spacing signal to circuit L1. Due to the condenser C2 the operation of the tube SA will cause the 10 tube SB to become extinguished. Also, the operation of tube SB will through the action of condenser C2 cause the tube SA to become extinguished.

When the operator at station B wishes to break or interrupt the operator at station A when he is sending, the operator at station B will open ,his

key and apply a spacing signal to the receiving circuit L2. The operator at station Awill thus know that the distant operator wishes to interrupt his sending and he will close the key 8 and apply a marking signal to the sending circuit L1.

This will place the line in condition for the transmission of signals from station B to station A. If

this spacing signal is received during the period when sending key 8 is closed, the sounder G will be put in spacing condition as long as the spacing signal is received, thus giving the operator at 8 is open, the tube RA will not operate since itsplate is opened up at key 8. When the operator closes his key 8, and the sounder 6 does not respond, he will have a positive indication that a break is coming over the line L2. The operator at station A will thus know that the distant operator wishes to interrupt his sending and he will close the key 8 and apply a marking signal to the sending circuit L1. This will place the line in condition for the transmission of signals from station B to station A.

As the operation of the arrangements at station B is identical with that already described for station A, no detailed description thereof will be a given.

.In Fig. 2 is shown an arrangement whereby the gas filled tube repeater device of the invention may be utilized to interconnect a two-way line of the polar duplex type to two one-way lines. The

two-way line L5 may be connected atits other end to a similar repeater of either the tube or relay type or the line may be the open or closed type of loop without a repeater as desired. The twoway line L5 and the two one-way lines Lu and L:

are connected together by the double Wheatstonebridge ACDF in a manner similar to a hybrid connection for voice frequency circuits. The sending line L6 and the receiving line L are connected at conjugate points AD and CF so as to prevent signals coming in over line L7 from being repeated back over line Le. The duplex line L5 L: will be received over resistance R1: or R14 and will cause the operation of either tube T3 or T4..

Because of the condenser C4 the operation of one of these tubes will cause the release of the other. '15 By means of battery B22 and resistance R15 or Rm the operation of one tube may apply a marking signal to line L5 and the operation of the other tube may apply'a spacing signal to line L5. In a like manner marking or spacing signals coming in over line Ls will be received over resistances R11 and R12 and may cause the operation of either tube T1 or T2. These tubes in like manner may then apply to line Le either marking or spacing As the details of operation are substantially similar to those already described with respect to Fig. 1 no further description thereof will be given.

While the invention has been disclosed as embodied in certain specific arrangements which are deemed desirable, it is understood that it is capabio of embodiment in many and other widely varied forms without departing from the spirit of the invention as defined by the appended claims.

What is claimed is:

1 1. In a telegraph system interconnecting two stations, a receiving circuit and a transmitting circuit at one of said stations, two gas filled discharge tubes each connected in difierent sides of said receiving circuit, means for operating one of said tubes when a marking signal is applied to said circuit at a distant station and the v cuits of said tubes through the primary windingof said transformer whereby the alternate operation of said tubes will not change the current -flow through said primary winding, and means for connecting said sending circuit to the secondary winding of said transformer.

2. In a telegraph system interconnecting two stations, a receiving circuit and a transmitting" circuit at one of said stations, two gas filled discharge tubes each connected in difierent sides I of said receiving circuit, means for operatingone of said tubes when a marking signal is applied to said circuit at a distant station and the other of said tubes when a spacing signal is applied to said circuit at the distant station, means controlled by the operation of either tube for causing the release of the other tube, plate circuits of equal impedance for each of said tubes,

receiving apparatus in one of said plate circuits, a transformer, means for completing the plate circuits of said tubes through the primary winding of said transformer whereby the reception of marking and spacing signals over said receiving circuit will not change the current flow through said primary winding, and means for connecting said sending circuit to the secondary winding of said transformer.

3. In a telegraph system interconnecting two stations, a receiving circuit and a transmitting circuit at one of said stations, two gas filled discharge tubes each connected in different sides of said receiving circuit, means for operating one of said tubes when a marking signal is applied to said circuit at a distant station and the other of said tubes when a spacing signal is applied to said circuit at the distant station, means controlled by the operation of either tube for causing the release of the other tube, plate circuits of equal impedance for each of said tubes, receiving apparatus in one of said plate circuits,

a transformer and transmitting apparatus,

means for completing the plate circuits of said tubes through the primary winding of said transformer whereby the reception of marking and spacing signals over said receiving circuit will not change the current flow through said primary winding, means for connecting said sending circuit to the secondary winding of said transformer, and means in said sending circuit for transmitting marking and spacing signals thereover, said last mentioned means being'controlled by the operation of said transmitting means.

4. In a telegraph system interconnecting two stations, a receiving circuit and a transmitting circuit at one of said stations, two gas filled discharge tubes each connected in difierent sides of said receiving circuit, means for operating one of said tubes when a marking signal is applied to said circuit at a distant station and the other of said tubes when a spacing signal is applied to said circuit at the distant station, means controlled by the operation of either tube for causing the release of the other tube, plate circuits of equal impedance for each of said tubes, receiving apparatus in one of said plate circuits, a transformer and transmitting apparatus, means for completing the plate circuits of said tubes through the primary winding of said transformer whereby the reception of marking and spacing signals over said receiving circuit will 30 not change the current flow through said primary winding, means for connecting said secondary winding of said transformer, two gas filled discharge tubes each connected in different sides of said transmitting circuit, means con- 35 trolled by the operation of one of said tubes for applying a marking signal to said sending circuit, means controlled by the operation of the other of said tubes for applying a spacing signal to said sending circuit, and means controlled by the operation of either one of said tubes in said sending circuit for causing the release of the other tube, the operation of said tubes in said sending circuit being controlled by the operation of said transmitting means. I

5. In a telegraph system interconnecting two stations, a receiving circuit and a transmitting circuit at one of said stations, two gas filled discharge tubes each connected in different sides of saidreceiving circuit, means for operating one of said tubes when a marking signal is applied to said circuit at a distant station and the other of said tubes when a spacing signal is applied to said circuit at the distant station, means controlled by the operation of either tube for causing the release of the other tube, plate circuits of equal impedance for each of said tubes, receiving apparatus in one of said plate circuits, a transformer and transmitting apparatus, means for completing the plate circuits of said tubes through the primary winding of said transformer whereby the reception of marking and spacing signals over said receiving circuit will not change the current flow through said primary winding, means for connecting said sending circuit to the secondary winding of said transformer, two gas filled discharge tubes each connected in different sides of said transmitting circuit, means controlled by the operation of one of said tubes for applying a marking signal to said sending circuit, means controlled by the operation of either one of said tubes in said sending circuit for causing the release of the other tube, means controlled by the operation of said transmitting apparatus when a marking signal is applied to said receiving circuit for controlling the operation of said receiving apparatus, and means controlled by the application of a spacing signal to said receiving circuit for preventing the operation of said transmitting apparatus from controlling the operation of said receiving apparatus.

- DAVID ERNEST BRANSON.

WILLIAM HENRY TOWNE HOLDEN. JAMES ALISON EYSTER. 

